scholarly journals Potential Link between Ectomycorrhizal Community Composition and Host Tree Phenology

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1719
Author(s):  
Tina Unuk Nahberger ◽  
Rok Damjanič ◽  
Hojka Kraigher ◽  
Tine Grebenc

The timing of leaf phenology tends to be crucial in controlling ecosystem processes such as the acquisition of carbon and water loss as well as in controlling tree nutrient cycling. To date, tree phenology has mostly been associated with environmental control (e.g., temperature and photoperiod) in a relationship with inheritance, while it has rarely been linked with ectomycorrhizal community compositional changes through the host tree’s phenological stages. Seasonal variations of fungal communities have been widely studied, but little is known about mycorrhiza community composition changes along phenological stages. Therefore, we analyzed ectomycorrhizal communities associated with silver fir and their compositional changes during the transition between phenological stages. The phenological stages of each individual tree and time of bud break were monitored weekly for two years and, at the same time, ectomycorrhiza was harvested from selected silver fir trees. In total, 60 soil cores were analyzed for differences in the ectomycorrhizal community between phenological stages using Sanger sequencing of individual ectomycorrhizal morphotypes. A significant difference in beta diversity for an overall ectomycorrhizal community was confirmed between analyzed time periods for both sampled years. Species-specific reactions to transitions between phenological stages were confirmed for 18 different ectomycorrhizal taxa, where a positive correlation of Russula ochroleuca, Russula illota, Tomentella sublilacina, and Tylospora fibrillosa was observed with the phenological stage of bud burst.

Mycorrhiza ◽  
2020 ◽  
Vol 30 (5) ◽  
pp. 541-553
Author(s):  
Tanja Mrak ◽  
Emira Hukić ◽  
Ines Štraus ◽  
Tina Unuk Nahberger ◽  
Hojka Kraigher

HortScience ◽  
2014 ◽  
Vol 49 (3) ◽  
pp. 254-259 ◽  
Author(s):  
Penelope F. Measham ◽  
Audrey G. Quentin ◽  
Nicholas MacNair

Growers naturally adapt and manage production for unpredictable and variable seasonal climates; however, the projected changes in climate introduce a new concern with increased variability in the frequency and severity of extreme climatic events and sustained changes in temperature. This study addresses the complexity of providing clear winter chill information in a form that facilitates grower assimilation and application of that information, ultimately to assist decision-making around variety selection and management. This study established the chill requirement for two commonly grown sweet cherry (Prunus avium L.) varieties: ‘Kordia’ and ‘Sweetheart’, and explored the uniformity of bud burst in each. It was found that varieties required different chill hours and that ‘Sweetheart’ reached mean time to, and maximum total bud burst, faster than ‘Kordia’, but no subsequent impact on uniformity of maturity at harvest. There was no significant difference in uniformity of burst between the two varieties. The results obtained by matching chill accumulation to tree phenology showed that cherry-producing regions in Australia will experience sufficient chill to support the production of the variety ‘Sweetheart’ with an increase in mean winter temperature of 1 °C. Regions in Western Australia and Queensland will become marginal, or not suitable, for ‘Kordia’.


2019 ◽  
Vol 11 (22) ◽  
pp. 2614 ◽  
Author(s):  
Nina Amiri ◽  
Peter Krzystek ◽  
Marco Heurich ◽  
Andrew Skidmore

Knowledge about forest structures, particularly of deadwood, is fundamental for understanding, protecting, and conserving forest biodiversity. While individual tree-based approaches using single wavelength airborne laserscanning (ALS) can successfully distinguish broadleaf and coniferous trees, they still perform multiple tree species classifications with limited accuracy. Moreover, the mapping of standing dead trees is becoming increasingly important for damage calculation after pest infestation or biodiversity assessment. Recent advances in sensor technology have led to the development of new ALS systems that provide up to three different wavelengths. In this study, we present a novel method which classifies three tree species (Norway spruce, European beech, Silver fir), and dead spruce trees with crowns using full waveform ALS data acquired from three different sensors (wavelengths 532 nm, 1064 nm, 1550 nm). The ALS data were acquired in the Bavarian Forest National Park (Germany) under leaf-on conditions with a maximum point density of 200 points/m 2 . To avoid overfitting of the classifier and to find the most prominent features, we embed a forward feature selection method. We tested our classification procedure using 20 sample plots with 586 measured reference trees. Using single wavelength datasets, the highest accuracy achieved was 74% (wavelength = 1064 nm), followed by 69% (wavelength = 1550 nm) and 65% (wavelength = 532 nm). An improvement of 8–17% over single wavelength datasets was achieved when the multi wavelength data were used. Overall, the contribution of the waveform-based features to the classification accuracy was higher than that of the geometric features by approximately 10%. Our results show that the features derived from a multi wavelength ALS point cloud significantly improve the detailed mapping of tree species and standing dead trees.


2021 ◽  
Author(s):  
Jim Downie ◽  
Andy F. S. Taylor ◽  
Glenn Iason ◽  
Ben Moore ◽  
Jonathan Silvertown ◽  
...  

2021 ◽  
Vol 13 (12) ◽  
pp. 2239
Author(s):  
Ying Quan ◽  
Mingze Li ◽  
Yuanshuo Hao ◽  
Bin Wang

As a common form of light detection and ranging (LiDAR) in forestry applications, the canopy height model (CHM) provides the elevation distribution of aboveground vegetation. A CHM is traditionally generated by interpolating all the first LiDAR echoes. However, the first echo cannot accurately represent the canopy surface, and the resulting large amount of noise (data pits) also reduce the CHM quality. Although previous studies concentrate on many pit-filling methods, the applicability of these methods in high-resolution unmanned aerial vehicle laser scanning (UAVLS)-derived CHMs has not been revealed. This study selected eight widely used, recently developed, representative pit-filling methods, namely first-echo interpolation, smooth filtering (mean, medium and Gaussian), highest point interpolation, pit-free algorithm, spike-free algorithm and graph-based progressive morphological filtering (GPMF). A comprehensive evaluation framework was implemented, including a quantitative evaluation using simulation data and an additional application evaluation using UAVLS data. The results indicated that the spike-free algorithm and GPMF had excellent visual performances and were closest to the real canopy surface (root mean square error (RMSE) of simulated data were 0.1578 m and 0.1093 m, respectively; RMSE of UAVLS data were 0.3179 m and 0.4379 m, respectively). Compared with the first-echo method, the accuracies of the spike-free algorithm and GPMF improved by approximately 23% and 22%, respectively. The pit-free algorithm and highest point interpolation method also have advantages in high-resolution CHM generation. The global smooth filter method based on the first-echo CHM reduced the average canopy height by approximately 7.73%. Coniferous forests require more pit-filling than broad-leaved forests and mixed forests. Although the results of individual tree applications indicated that there was no significant difference between these methods except the median filter method, pit-filling is still of great significance for generating high-resolution CHMs. This study provides guidance for using high-resolution UAVLS in forestry applications.


2018 ◽  
Vol 26 (1) ◽  
pp. 51-62
Author(s):  
Małgorzata Buśko

Abstract The paper presents procedures for determining market values of forest real properties, with particular emphasis placed on the forest stand. The mixed-approach valuation procedure - land valuation index method - was analyzed. The practical part of the work regarding the valuation of the forest stand introduces the various techniques of valuation and acquisition of data on forest resources used, i.e.: index-based valuation approach and stock survey approach. The subject of the research is part of a forest property, which represents an assessment area, typical of the southern part of Poland, located in the Tenczynek Forest Division. There is a forest management plan for the analyzed property which, together with the assessment descriptions, was used as one of the sources of data for valuation. The second source of data for valuation were direct field surveys, i.e.: geodetic surveys for determining the assessment area and the stock survey approach with individual tree assessment with respect to data on the stand. Based on the research, it may be concluded that both valuation techniques and methods used to capture data on forest resources significantly affect the final value of forest properties. The market value of the stand, determined by the index-based valuation approach, demonstrates a significant difference when compared to the value of the stand determined by the stock survey approach. The forest management plan should only be used as a supplementary material and only to identify site types of forests by property valuers and, partially, together with economic maps, to determine the boundaries of assessment areas.


2019 ◽  
Author(s):  
Micha Weil ◽  
Haitao Wang ◽  
Mia Bengtsson ◽  
Daniel Köhn ◽  
Anke Günther ◽  
...  

AbstractDrained peatlands are significant sources of the greenhouse gas (GHG) carbon dioxide. Rewetting is a proven strategy to protect carbon stocks; however, it can lead to increased emissions of the potent GHG methane. The response to rewetting of soil microbiomes as drivers of these processes is poorly understood, as are biotic and abiotic factors that control community composition.We analyzed the pro- and eukaryotic microbiomes of three contrasting pairs of minerotrophic fens subject to decade-long drainage and subsequent rewetting. Also, abiotic soil properties including moisture, dissolved organic matter, methane fluxes and ecosystem respiration rates.The composition of the microbiomes was fen-type-specific, but all rewetted sites showed higher abundance of anaerobic taxa compared to drained sites. Based on multi-variate statistics and network analyses we identified soil moisture as major driver of community composition. Furthermore, salinity drove the separation between coastal and freshwater fen communities. Methanogens were more than tenfold more abundant in rewetted than in drained sites, while their abundance was lowest in the coastal fen, likely due to competition with sulfate reducers. The microbiome compositions were reflected in methane fluxes from the sites. Our results shed light on the factors that structure fen microbiomes via environmental filtering.


2014 ◽  
Author(s):  
Gabriela Garcia ◽  
Sarah Gabriele ◽  
Benjamin Cowgill ◽  
Xavier Rodriguez ◽  
Robert J Gay

Background: The purpose of this study was to determine what floral differences exist in North Mountain Park and Casa Grande Mountain Park which are both located on opposite sides of the Casa Grande Valley, Pinal County, Arizona and to attempt to explain any measured differences. Previous authors have proposed several explanations for floral variation within the Sonoran Desert including elevation, soil pH, and mineral content. This study explicitly tests several of these proposed mechanisms for determining community composition. Methods: The floral composition was measured in both North Mountain Park and Casa Grande Mountain Park through a series of transects which were sampled by multiple times in 2012 and 2013. Elevation data soil pH were also sampled. Results: The data recovered from North Mountain Park differed from the expected values in Casa Grande Mountain Park by 22%. This indicates a significant difference in the flora between these two localities that was not predicted by earlier studies. Elevation and soil pH differences between sampled localities were not significant. This suggests that mineral composition of the soil may play an important role within this basin in determining community composition. Discussion: Many factors that have been proposed in prior studies do not appear to play a significant role within the Casa Grande Valley in determining community composition. This indicates that the composition of a community is influenced by different factors in different locations within the Sonoran Desert. This makes determining overall controlling factors across an ecosystem difficult.


Author(s):  
Agnès Destrac-Irvine ◽  
Gérard Barbeau ◽  
Laure De Resseguier ◽  
Thierry Dufourcq ◽  
Vincent Dumas ◽  
...  

Phenology is concerned with the periodic phenomenon of the vine growing cycle (bud burst, flowering, veraison (color change), in relation to the climate.  It is a veritable biological clock of the vines.   The timing of the numerous operations in the vineyard (phytosanitary protection, defoliation, crop thinning….) is undertaken in accordance with the phenological stages. Since the precociousness of the latter is directly linked to the temperature, the phenology is also a marker of global warming.


2018 ◽  
Vol 5 (4) ◽  
pp. 171503 ◽  
Author(s):  
Amanda M. Koltz ◽  
Niels M. Schmidt ◽  
Toke T. Høye

The Arctic is experiencing some of the fastest rates of warming on the planet. Although many studies have documented responses to such warming by individual species, the idiosyncratic nature of these findings has prevented us from extrapolating them to community-level predictions. Here, we leverage the availability of a long-term dataset from Zackenberg, Greenland (593 700 specimens collected between 1996 and 2014), to investigate how climate parameters influence the abundance of different arthropod groups and overall community composition. We find that variation in mean seasonal temperatures, winter duration and winter freeze–thaw events is correlated with taxon-specific and habitat-dependent changes in arthropod abundances. In addition, we find that arthropod communities have exhibited compositional changes consistent with the expected effects of recent shifts towards warmer active seasons and fewer freeze–thaw events in NE Greenland. Changes in community composition are up to five times more extreme in drier than wet habitats, with herbivores and parasitoids generally increasing in abundance, while the opposite is true for surface detritivores. These results suggest that species interactions and food web dynamics are changing in the Arctic, with potential implications for key ecosystem processes such as decomposition, nutrient cycling and primary productivity.


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